1. Field of the Invention
The present invention relates to a structural method of mounting components into a computer housing. More precisely, the present invention relates to a thumb screw assembly allowing the installation and removal of components in the computer housing, without the use of tools.
2. Background of the Relevant Art
The present invention relates to a fastener. It is particularly beneficial for securing components in a computer system such as a server. The following background and description of the preferred embodiments describes the fastener in that context. However, the scope of the preferred embodiments and the claims which follow should not be so limited, unless otherwise explicitly stated.
The necessity for specialized computer equipment has increased dramatically over recent years. Corporations, both large and small, as well as individual consumers have come to depend on computers to enhance and assist them in a broad assortment of tasks. For the individual or small business, personal computers are typically relatively compact and streamlined, often comprising a monitor, a keyboard, a mouse, and a CPU “box” that sits on a desktop or on the floor. These personal computers, although considered compact when deployed in relatively small numbers, can be quite cumbersome and bulky when deployed in larger quantities. It is not uncommon for an organization to require several computers to act as servers controlling their local area networks. For larger corporations that require numerous servers, the traditional CPU package is not practical to house servers. For such operations, an industry standard EIA (Electronics Industries Alliance) rack is often used to contain servers in a stacked arrangement that uses the available space more efficiently.
Such electronics racks are relatively simple structures that closely resemble an open-frame cabinet without shelves. Computer server/component racks are typically constructed with perforated, hinged front-doors, rigid sides and a removable rear panel. Industry standard 19″ EIA electronics racks are designed typically to house a column of electronics packages that are 17¾″ in width and with varying depths. The height of an electronics package can vary but, to be compatable with the rack mounting structure, must be an integer multiple of an EIA unit called simply the “U.” An EIA U is 1.75 inches. Electronic equipment generally has a height in multiples of “Us” e.g., 1U (1.75″), 2U (3.50″), 3U (5.25″), etc. Although it is preferred that the height of the electronics components be a multiple of the standard EIA unit U, the dimension of the EIA unit is understood to represent a maximum allowable height, including both the height of the component and any clearance required. This amount of clearance aides in the installation of the rack mounted electronics and promotes interference free insertion and removal.
Typically, electronic components may be secured within the rack using a pair of drawer slides. The drawer slides, usually ball-bearing supported rails, are secured in place within the rack frame. Corresponding rails are located on the side surfaces of the electronics component to be mounted, thus allowing the component to be pulled in and out of the rack frame easily to allow quick and frequent access.
As the computing needs of both large and small businesses increase, there is increasing demand for computer servers to become smaller and more compact. This demand is coupled with the demand that the systems be easier to maintain and service. A typical server comprises at least one, and often more than one, of each of the following components: system board including processors and memory; power supplies; disk drives, including hard disks, floppy drives, CD-ROM drives, etc.; peripheral component interface (PCI) buses, and cooling fans. These components are typically manufactured separate from the computer housing or chassis, and then they are mounted in the computer chassis during final assembly.
Mounting all of these components in a densely packed server, some as small as 1U or 2U, creates many interface issues associated with maintaining and accessing the server. For example, the chassis may have a slot positioned to receive some components (e.g., a disk drive or CD-ROM drive), or the chassis may have a connector to receive other components (e.g., PCI assemblies). Several components may be coupled to the chassis with a bracket. When the component is a disk drive or a CD-ROM drive, the slot in the chassis receives the bracket to couple the component to the chassis. When the component is a PCI assembly (including PCI card and cage), the bracket may be secured to the chassis using fasteners.
One conventional method for installing a plurality of PCI assemblies in a computer chassis involves attaching a mounting bracket to each PCI assembly and then individually connecting each bracket to the chassis with a threaded fastener. Each threaded fastener passes through an aperture in the bracket and is secured in a threaded hole in the chassis to clamp the bracket to the chassis and restrict relative motion between the PCI assembly and the chassis. Such a method may be employed by a manufacturer of custom computers to produce computers that have various numbers of PCI assemblies.
One drawback with the foregoing approach is that the fasteners may accidentally fall into the spaces between neighboring assemblies and may be difficult to retrieve without removing the assemblies from the chassis.
Another drawback is that the installed fastener may not extend further than the tallest component (typically the PCI cage) due to chassis size constraints. As discussed above, there is increasing demand for servers to become smaller. Because the chassis is the frame, which holds the computer components, it is desirable for it to have a minimum height. However, the chassis size is limited by the tallest component (PCI cage) within it. As a result, the installed fastener is designed to sit flush with the surrounding components. In order to tighten the fastener in place, a fastening tool, such as a screwdriver, may be required to ensure that the fastener is fully secured and sits flush with its surrounding components. Although generally satisfactory, it would be even more desirable to operate the fastener without tools. Tool-less installation is particularly desirable for large systems that require frequent service. The use of a tool is undesirable because it is inconvenient and may slip and damage the PCI assembly or other components during installation.
Therefore, there remains a need in the art for an arrangement that allows for easy installation and removal of components from a server computer without using any tools. The present invention overcomes the deficiencies of the prior art while focusing on these needs.